Prime Minister Malcolm Turnbull has been rallying support for the controversial Trans-Pacific Partnership in Washington DC in an attempt to combat an "extraordinary counsel of despair" on the issue.
The regional trade deal involving 12 countries, including the US and Australia, is deeply unpopular in America.
Presidential hopefuls on both sides of politics are at pains to distance themselves from the agreement, which is unlikely to pass Congress before the November poll.
On the second day of his US official visit, Mr Turnbull challenged US business and congressional leaders to jump on the bandwagon.
President Barack Obama was singing from the same song sheet at the start of bilateral talks at the White House on Tuesday (Wednesday morning AEDT).
"It is going to be good for our economy, it is going to be good for our workers and our businesses," he told reporters in the Oval Office.
Mr Turnbull said it was important US powerbrokers didn't lose sight of the wood for the trees.
"The TPP is important for our world, it is important for America," he said.
The prime minister dismissed analysis the deal would have only marginal benefits to the economic growth of individual countries, saying some things couldn't be measured.
The deal would set a high bar for some countries to step up under a rules-based and transparent system.
Mr Turnbull questioned why the US, the country which created globalisation, appeared fearful of free trade.
It should be confident that as more markets opened up globally its businessmen and women, entrepreneurs, engineers and scientists would be able to "compete with the very best and outpace most of them".
"The reality is the TPP offers opportunity for the United States and there is very little at risk and so much to gain in the region," he said.
"Some people say 'Well, you open markets even just a little bit, who knows what will happen?'
"What an extraordinary counsel of despair."
Mr Turnbull received a polite and receptive hearing from congressional leaders on the TPP issue on Tuesday afternoon.
Senators were particularly concerned with how biologics and tobacco are dealt with.
The 30-chapter TPP agreement includes elimination and reduction of about 18,000 tariffs on industrial and agricultural goods, including textiles and clothing; rules on trade in services and financial goods; and commitments on the free flow of internet and digital commerce.
It sets out rules for patents, trademarks and other intellectual property across the trade zone, including specific provisions about pharmaceuticals, and enforces labour and environmental standards.
